Subject: how do I make my home-made electric generator more efficient?

I am experimenting with generating electricity and have devised a simple 
installation which generates electricity via a dynamo and a rotating 
wheel. Very much akin to that which you would find on a bicycle. However, 
when checked with a multimeter I appear to generate more amps when 
rotating the wheel slowly as opposed to a higher rpm. Furthermore the 
voltage drops. Am I reading the multimeter right? I assumed the higher the 
rpm the more energy I would generate. For, when I connect a light bulb to 
the circuit, the faster I rotate the wheel the more light is emitted from 
the bulb. Please can you explain whats going on!!! I'm confused!! 

Re: how do I make my home-made electric generator more efficient?